diff --git a/DDG4/include/DDG4/Geant4FastSimShowerModel.h b/DDG4/include/DDG4/Geant4FastSimShowerModel.h
index 2089b4fad8b9a5741cfa2413a05b2f016106698a..e8677389efe2d7b78e6a7bb455fc53ad8a417331 100644
--- a/DDG4/include/DDG4/Geant4FastSimShowerModel.h
+++ b/DDG4/include/DDG4/Geant4FastSimShowerModel.h
@@ -52,7 +52,7 @@ namespace dd4hep  {
       // typedef std::vector<std::pair<std::string, double> > ParticleConfig;
       typedef std::map<const G4ParticleDefinition*, double> ParticleCut;
       typedef std::map<std::string, std::string> ParticleConfig;
-      typedef std::unique_ptr<Geant4ShowerModelWrapper> Wrapper;
+      typedef Geant4ShowerModelWrapper* Wrapper;
   
       /// Property: Region name to which this parametrization should be applied
       std::string    m_regionName     { "Region-name-not-specified"};
@@ -78,7 +78,7 @@ namespace dd4hep  {
       /// Reference to the G4 fast simulation model
       G4VFastSimulationModel* m_model { nullptr };
       /// Reference to the shower model
-      Wrapper        m_wrapper        { };
+      Wrapper        m_wrapper        { nullptr };
 
     protected:
       /// Define standard assignments and constructors
diff --git a/DDG4/src/Geant4FastSimShowerModel.cpp b/DDG4/src/Geant4FastSimShowerModel.cpp
index 9aa4edf3e3df338de2ddb334533d664f6c9e5052..ee9d54d8b09ad3c9b526465020a02dcfbdaf502e 100644
--- a/DDG4/src/Geant4FastSimShowerModel.cpp
+++ b/DDG4/src/Geant4FastSimShowerModel.cpp
@@ -99,13 +99,13 @@ Geant4FastSimShowerModel::Geant4FastSimShowerModel(Geant4Context* ctxt, const st
   this->declareProperty("Emax",                this->m_eMax);
   this->declareProperty("Ekill",               this->m_eKill);
   this->declareProperty("Etrigger",            this->m_eTriggerNames);
-  this->m_wrapper.reset(new Geant4ShowerModelWrapper(this));
+  this->m_wrapper= new Geant4ShowerModelWrapper(this);
 }
 
 /// Default destructor
 Geant4FastSimShowerModel::~Geant4FastSimShowerModel()    {
   detail::deletePtr(m_model);
-  m_wrapper.reset();
+  detail::deletePtr(m_wrapper);
 }
 
 /// Access particle definition from string
@@ -163,7 +163,7 @@ void Geant4FastSimShowerModel::addShowerModel(G4Region* region)     {
   if ( m_model )
     fastsimManager->AddFastSimulationModel(m_model);
   else if ( m_wrapper )
-    fastsimManager->AddFastSimulationModel(m_wrapper.get());
+    fastsimManager->AddFastSimulationModel(m_wrapper);
   else
     except("Geant4FastSimShowerModel::addShowerModel: Invalid shower model reference!");
 }